In order to improve product quality and eliminate spots, surface degreasing and cleaning processes are required. The components and properties of lubricants are very important for surface degreasing and cleaning. The pollution spots formed on the surface of seamless steel pipes can be divided into 3 categories according to the substances causing pollution:
1) Oily pollution - oil, grease and fatty acids;
2) Water-soluble pollution - organic and inorganic acids;
3) Solid pollution - oxides, particles and dust, etc.
Surface degreasing method of seamless pipe:
1) The formula of the degreasing solution is: each liter of solution contains 20g-30g of sodium hydroxide, 35g-50g of sodium nitrate, and 3g-5g of sodium silicate.
2) The operating process requirements are: the liquid temperature is 70 ℃ ~ 80 ℃, and the soaking time is determined by the test method according to the amount of oil on the surface of the pipe, generally about 10 minutes to 40 minutes. The heating method can be steam.
3) Seamless pipes can be inspected by any of the following methods
a. Wipe the surface of the seamless tube with clean and dry white filter paper, if there is no trace of grease on the paper, it is qualified;
b. Use 100% camphor below 1mm to check the steam to flush the condensate, and it is qualified to keep rotating;
c. Check the surface of the seamless tube with ultraviolet rays with a wavelength of 3200-3800 angstroms, and the grease-free fluorescence is qualified. After degreasing treatment, the oil pollution on the pipe surface can be removed.